A coupled production of propene oxide and methyl tert-butyl ether (MTBE) is known from the prior art using the so called Halcon process, where iso-butane is oxidized with air to tert-butyl hydroperoxide, which is then reacted with propene in the presence of a molybdate catalyst to give propene oxide and tert-butanol. The tert-butanol is further reacted with methanol to give MTBE. However, such a coupled production, where both products are obtained at an essentially fixed ratio, has a disadvantage when market demand for the two products does not match this product ratio. Since the demand for propene oxide has grown more rapidly in recent years than the demand for MTBE, the HPPO process for making propene oxide from propene and hydrogen peroxide has been developed as a stand-alone process for making propene oxide. However, separate production lines for MTBE and propene oxide by the HPPO process require more raw material than the coupled production of propene oxide and MTBE by the Halcon process.